title: Pre-stimulus activity predicts the winner of top-down vs. bottom-up attentional selection.
abstract: Our ability to process visual information is fundamentally limited. This leads to competition between sensory information that is relevant for top-down goals and sensory information that is perceptually salient, but task-irrelevant. The aim of the present study was to identify, from EEG recordings, pre-stimulus and pre-saccadic neural activity that could predict whether top-down or bottom-up processes would win the competition for attention on a trial-by-trial basis. We employed a visual search paradigm in which a lateralized low contrast target appeared alone, or with a low (i.e., non-salient) or high contrast (i.e., salient) distractor. Trials with a salient distractor were of primary interest due to the strong competition between top-down knowledge and bottom-up attentional capture. Our results demonstrated that 1) in the 1-sec pre-stimulus interval, frontal alpha (8-12 Hz) activity was higher on trials where the salient distractor captured attention and the first saccade (bottom-up win); and 2) there was a transient pre-saccadic increase in posterior-parietal alpha (7-8 Hz) activity on trials where the first saccade went to the target (top-down win). We propose that the high frontal alpha reflects a disengagement of attentional control whereas the transient posterior alpha time-locked to the saccade indicates sensory inhibition of the salient distractor and suppression of bottom-up oculomotor capture.
authors.affiliation: Center for Mind and Brain, University of California Davis, Davis, California, United States of America. a.mazaheri@donders.ru.nl
authors.forename: Ali
authors.initials: A
authors.lastname: Mazaheri
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: DiQuattro
authors.forename: Jesse
authors.initials: J
authors.lastname: Bengson
authors.forename: Joy J
authors.initials: JJ
authors.lastname: Geng
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D008954:Models, Biological; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult